// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.

using System;
using System.ComponentModel;
using System.Globalization;

namespace Microsoft.Practices.EnterpriseLibrary.Common.Configuration
{
    /// <summary>
    /// Represents a configuration converter that converts a byte array to and from a string representation by using base64 encoding.
    /// </summary>
    public class ByteArrayTypeConverter : TypeConverter
    {
        /// <summary>
        /// Returns whether this converter can convert an object of the given type to the type of this converter. 
        /// </summary>
        /// <param name="context">An <see cref="ITypeDescriptorContext"/> object.</param>
        /// <param name="sourceType">A <see cref="Type"/> that represents the type you want to convert from. </param>
        /// <returns><see langword="true"/> if this converter can perform the conversion; otherwise, <see langword="falase"/>. </returns>
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
        {
            return typeof(string) == sourceType;
        }

        /// <summary>
        /// Converts the given value to the type of this converter.
        /// </summary>
        /// <param name="context">An <see cref="ITypeDescriptorContext"/> object.</param>
        /// <param name="culture">A <see cref="CultureInfo"/> object.</param>
        /// <param name="value">An <see cref="Object"/> that represents the converted value. </param>
        /// <returns>An <see cref="Object"/> that represents the converted value. </returns>
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
        {
            return Convert.FromBase64String((string) value);
        }

        /// <summary>
        /// Returns whether this converter can convert the object to the specified type. 
        /// </summary>
        /// <param name="context">An <see cref="ITypeDescriptorContext"/> object.</param>
        /// <param name="destinationType">A <see cref="Type"/> that represents the type you want to convert to..</param>
        /// <returns><b>true</b> if the converter can convert to the specified type, <b>false</b> otherwise.</returns>
        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
        {
            return typeof(byte[]) == destinationType;
        }

        /// <summary>
        /// Converts the given value object to the specified type, using the arguments. 
        /// </summary>
        /// <param name="context">An <see cref="ITypeDescriptorContext"/> object.</param>
        /// <param name="culture">A <see cref="CultureInfo"/> object.</param>
        /// <param name="value">The <see cref="Object"/> to convert.</param>
        /// <param name="destinationType">The <see cref="Type"/> to convert the value parameter to.</param>
        /// <returns>The converted value.</returns>
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
        {
            return Convert.ToBase64String((byte[])value);
        }
    }
}

